JPS63129162A - Intake manifold for internal combustion engine - Google Patents

Abstract

PURPOSE:To effectively promote the atomization of fuel while to prevent an intake amount of air from its decrease, by providing almost ring-shaped protrusive streak parts, in which one part of the peripheral part corresponding to the branch direction of a branch port is divided by a space, in a branch part upstream internal peripheral wall of the branch port. CONSTITUTION:Fuel in an intake manifold exists mixing with atomized fuel, floating in a pipe, in a wall flow adhering to a pipe internal wall. And, for instance, the wall flow, transmitted along a surface corresponding to a direction crossing at a right angle with the branch direction of branch ports 4, 5 in the pipe, hits respectively corresponding protrusive streak parts 12a, 12b. As the result, the wall flow is separated into a part, in which the fuel is atomized by an air stream in point ends of the protrusive streak parts 12a, 12b, and a part, in which the fuel, being guided by the protrusive streak parts 12a, 12b and to their space part 13, is introduced to a branch part 8 moving along the pipe internal wall from the space part 13 being left as in a state of the wall flow by the air stream. Accordingly, the intake manifold enables the uniform wall flow to be supplied to each port while the atomization of the fuel to be effectively promoted.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an improvement in an intake manifold that guides an air-fuel mixture to each cylinder of a multi-cylinder internal combustion engine.

(Prior art) This type of intake manifold is, for example, shown in Figs.
There is something like the one shown in Figure 11.
(See Publication No. 954, etc.).

That is, in these figures, the riser part 1 has a curved passage part 2.
, 3 are connected, and branch ports 4, 5 and 6.7, which connect to each cylinder, branch from the curved passage portion 2.3.

Then, the liquid fuel adhering to the inner circumferential wall of the branch port 4.5 and 6.7 is directed to the inner circumferential wall of the curved passage portion 2.3 near the upstream side of the branch portion 8 of the branch port 4.5 and 6.7. A protrusion 9 is formed in the shape of a continuous ring that gathers and guides the protrusion 9 toward the center of the branch 8 and has an acute angle.

(Problems to be Solved by the Invention) However, in such a conventional intake manifold of an internal combustion engine, as shown in FIGS. Most of the fuel is guided to the tip of the acute-angled protrusion 9, and the fuel is scattered by the air flowing inside the intake manifold, which causes the following problems.

That is, in order to disperse the fuel sufficiently, it is necessary to make the protrusion 9 larger, but if this is done, the inner diameter of the intake manifold will be further narrowed, which will reduce the amount of intake air during high-speed operation. There was a problem with it being put away.

Furthermore, if the projections 9 were made small, there was a problem in that the fuel could not be sufficiently dispersed and the fuel could not be atomized sufficiently.

Therefore, in view of the conventional situation, the present invention solves the above-mentioned conventional problems by improving the shape of the protrusion provided on the inner circumferential wall on the upstream side of the branching part of the branching port, thereby improving the flow treatment on the inner wall of the pipe. With the goal.

Means for Solving Problems> For this reason, the present invention provides an intake manifold that guides an air-fuel mixture to each cylinder of a multi-cylinder internal combustion engine. The structure is such that a part of the circumferential portion corresponding to the ring is provided with a substantially ring-shaped protruding portion separated by a gap.

<Function> For example, the wall flow that travels along the surface corresponding to the direction perpendicular to the branching direction of the branch port in the pipe hits the corresponding ridges, and is atomized by the air flow at the tips of the ridges. It is divided into those that are guided by the ridges, are guided to the gaps in the ridges, and are guided from the gaps through the inner wall of the pipe as a wall flow by the air flow to the branching section. .

Therefore, a uniform wall flow can be supplied to each port, and the particles can be effectively atomized.

<Example> Hereinafter, an example of the present invention will be described based on FIGS. 1 to 8.

1 to 3, the riser section 1 has a curved passage section 2.
The configuration in which the curved passage portions 2 and 3 are connected to branch ports 4, 5 and 6, 7 that connect to each cylinder is similar to the conventional example.

Then, on the inner circumferential wall of the curved passage parts 2 and 3 on the upstream side of the branch part 8 of the branch ports 4, 5, 6, and 7, there are arranged on the inner circumferential wall of the curved passage parts 2, 3 on the upstream side of the branch part 8 of the branch ports 4, 5, 6, and 7, and that correspond to the branching direction of the branch ports 4, 5, 6, and 7. A protruding strip 12 is provided which has a substantially ring shape, with a portion of its circumferential portion divided by a gap 13. Note that only the protrusion 12 on the side of the curved passage section 2 is shown, and since the protrusion section on the side of the curved passage section 3 has a similar structure, only the protrusion 12 will be explained below.

Each of the protrusions 12 is a horseshoe-shaped upper protrusion 12a.
and a lower protrusion 12b.

The upper protruding portion 12a and the lower protruding portion 12b each rise perpendicularly from the inner circumferential wall of the curved passage portion 2, and are connected to the inner circumferential wall surface via an arcuate surface having a predetermined radius, which will be described later. It is formed into a circular arc surface with a predetermined radius.

FIG. 4 shows a cross section of the tips of both of the protrusions 12a, 12b, and shows the protrusions 12a, 12b and the curved passage part 2.
The radius R of the arcuate surface between the inner circumferential wall surface and the inner peripheral wall surface is set to 1 to 2 fins, and the radius R of the arcuate surface at the tip of the protrusion portion is set to 2 fins or less. Further, the thickness t of the protruding portion is set to be 31 cm or less, and the height h is set to 4 to 611 cm. Further, the length G of the gap 13 between the protrusions 12 shown in FIG. 2 is set to 6 to 12 fl.

Note that the shapes of the corners 12c at both circumferential ends of each of the protrusions 12a and 12b are not particularly limited, and may be edges.

Further, as shown in FIG. 3, the inner diameter D2 of the constricted portion of the pipe formed by providing the protrusion 12 is determined from the required output of the engine, and then The inner diameter of the pipe is determined so as to prevent a decrease in the amount of intake air due to the restriction of the pipe formed by providing the protrusion 12.

Next, the functions and effects of this embodiment will be explained.

As shown in FIGS. 2 and 3, the fuel in the intake manifold is a mixture of atomized fuel floating in the pipe and wall flow adhering to the inner wall of the pipe.

For example, the wall flow that travels on the surfaces corresponding to the direction perpendicular to the branching direction of the branch port 4.5 in the pipe, that is, the upper and lower surfaces of the pipe in the figure, hits the corresponding protrusions 12a and 12b, so that The particles that are atomized by the air flow at the ends of the protrusions 12a and 12b spirally flow inside the tube and are guided by the protrusions 12a and 12b to the gap 13 between the protrusions 12a and 12b. The air flows through the gap 13 and is separated into a wall flow that is guided along the inner wall of the pipe and guided to the branch portion 8.

As shown in Fig. 1, the fuel traveling along the inner wall of the pipe is directed to cylinder 13 for the branch port 5 side wall flow, and to l' for the branch port 4 side wall flow.
It flows into each of the four cylinders.

Therefore, according to this configuration, a part of the wall flow fuel adhering to the inner wall of the pipe can be evenly supplied to each port 4.5, and other wall flow fuel can be effectively atomized.

In particular, in this embodiment, the protrusion and the inner circumferential wall of the curved passage section 2 are connected via an arcuate surface, and the tip of the protrusion is formed into an arcuate surface. The traveling wall flow is smoothly guided by the ridges.

FIG. 5 shows another embodiment.

That is, in this embodiment, the intermediate portion of the circumferential length of the lower projecting portion 12b is divided to provide a gap portion 14, so that a portion of the wall flow on the lower surface of the pipe flows out. ing.

This embodiment is effective under extremely low temperature conditions, where the wall flow is extremely large and the air flow inside the pipe is slow, and the wall flow outflow from the gap 13 between the upper and lower protruding plates 12a and 12b is small. Improves starting performance.

In order to evenly distribute the fuel at the branch portion 8 to each cylinder, it is better to have a small amount of wall flow on the lower and upper surfaces of the pipe. This is because the fuel in the branch section 8 is affected by the pulsation of each cylinder and the surface roughness and dimensional accuracy of the inner wall surface of the pipe during manufacturing, and it is difficult to distribute the fuel equally to each cylinder. Therefore, the length gl of the gap 14 is preferably as small as possible, and should be within 4fi.

FIG. 6 shows still another embodiment, in which the lower protrusion 1
A relatively large gap 15 is provided by dividing the middle part of the circumferential length of the tube 2b, and a protrusion 1 of one dimension from the inner bottom surface of the tube is provided.
6. In addition, g2 is 4 to 6 cranes, and l is 1 to 6 cranes.
Set to 3N.

Such an embodiment can cope with cases where the intake manifold is inclined (for example, on a mountain road) and with rough machining accuracy of the inner wall surface of the pipe. β is provided to measure wall flow.

The present invention is not limited to a case where the cross-sectional shape of the intake passage is circular, but can also be applied to a case where the cross-sectional shape of the intake passage is oval, as shown in FIG. 7, for example.

Further, the protruding portions 12a and 12b are not limited to the horseshoe shape as in the above embodiment, but may have other shapes such as a crescent shape as shown in FIG.

<Effects of the Invention> As explained above, according to the present invention, in the intake manifold that guides the air-fuel mixture to each cylinder of a multi-cylinder internal combustion engine, the inner circumferential wall on the upstream side of the branching part of the branching port is provided with a seal in the branching direction of the branching port. A roughly ring-shaped protrusion is provided in which a part of the circumference corresponding to the gap is separated by a gap, and the fuel guided by the protrusion flows out from the gap as a wall flow, and the remaining fuel is Since the fuel is atomized from the tip of the ridge, fuel can be evenly distributed to each cylinder, and the output of each cylinder can be equalized, improving driveability, increasing output, improving startability, and simplifying exhaust measures. At the same time, atomization can be effectively achieved, and the problem of a decrease in the amount of intake air can be solved.

[Brief explanation of the drawing]

FIG. 1 is a plan sectional view showing an embodiment of an intake manifold of an internal combustion engine according to the present invention, and FIG. 2 is a 1-1g in FIG.
3 is a sectional view taken along line nn in FIG. 2, FIG. 4 is an enlarged sectional view of the protrusion in the same embodiment, and FIGS. 5 to 8 are sectional views showing other embodiments. , FIG. 9 is a plan sectional view showing an embodiment of an intake manifold of a conventional internal combustion engine, and FIG.
The figure is a sectional view taken along line X-X in Figure 9, and Figure 11 is a cross-sectional view of
-xn sectional view. 1... Riser part 2, 3... Curved passage part 4゜5.6.7... Branch port 8... Branch part 1
2゜12a, 12b... Protruding portion 13... Gap patent applicant Nissan Motor Co., Ltd. Representative Patent attorney Fujio Sasashima 1... Riser portion 2.3... Curved passage portion 4. 5.6.7...Branch port 8...Branch portions 12, 12a, ]2b-...Protrusion portion 13...Gap Fig. 1 ■→ Fig. 3 Fig. 4 Fig. 5 Fig. 6 Figure 7 Figure 8 Figure 9 Figure 10 Figure Summer Figure 11

Claims (1)

[Claims] A riser section connected to a fuel supply device, a curved passage section connected to the riser section, and a plurality of branch ports branching from the curved passage section, and a plurality of cylinders connected to the plurality of branch ports. In the intake manifold that guides the air-fuel mixture to the air-fuel mixture, the inner peripheral wall on the upstream side of the branching part of the branching port is provided with a protrusion having a substantially ring shape in which a part of the peripheral part corresponding to the branching direction of the branching port is divided with a gap. An intake manifold for an internal combustion engine, characterized by being provided with.